:Check: The relations are different, of course
The purpose is building in one mode and not having to check if it works in another.
Give the complex UIs that I build, simplistic "foregound" vs "background" stuff doesn't cut it.
Discussion
For me it's not simplistic at all, actually it's the hard part that requires ad hoc optimization for each theme.
From the preview I don't like very much the overall feeling, it remembers me a too darkened or really old/bad quality screen; but as usual, let's see the finished experience, best of luck with your work! :)